Lighting unit



Aug. 19 1924. 1,505,559

F. 1 GRANT LIGHTING UNIT Filed Feb. 16. 1923 t a 1mm Wziz a/zaw? J farazcc l firmzZ Patented Aug. 19, 1924.

UNITED STATES PATENT OFFICE.)

FLORENCE L. GRANT, OF CHICAGO, ILLINOIS, ASSIGNOR TO INLAND GLASS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OLE DELAWARE.

a LIGHTING UNIT.

Application filed February 16, 1923. Serial No. 619,504.

To all whom it may concern:

Be it known that I, FLoRnNoE L. GRANT, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Lighting Units, of which the following is a specification.

My invention relates to lighting units, and is incorporated in a one-piece totally enclosed element formed of glass having difi'erent surface characteristics at different portions of its surface. The object of the invention is to provide a device of this character .which will obtain maximum diffusion and maximum transmission of light at appropriate portions and protect the eyes of those in the room against excessive glare.

I obtain my object by the construction illustrated in the accompanying drawings, in which Figure l is an elevation partially from the side and partially in central vertical section of a complete unit embodying the invention.

Figure 2 is a view showing a fragment of the surface which is rippled.

Figure 3 is an enlarged sectional view taken on the line 33 Figure 2.

Like numerals denote like parts throughout the several views.

In my structure the upper portion 1 is in the form of a truncated cone surmounted by a collar 2 by which it may be secured to a suitable fixture. This upper portion of the unit occupies about half of the total height of the unit and is enamelled so that it will be semi-transparent but will not permit the image of the bulb filament to be distinguished. As the light emitted from this portion is thrown upward it produces a soft and diffused light, especially when refiected from a ceiling of light color. EX- tending downward from the lower end of the conical portion 1 is a cylindrical portion 3 which is enamelled like portion 1.

Extending inward from the lower end of the cylindrical portion is a converging portion 4, which is of rippled glass. This is a term employed in the trade to indicate an all-over pattern of the low ridges or wales which are indicated in Figures 2 and 3 by the numeral 6. These ridges are irregular ogee curves. The lass of this converging portion is preferably clear, but the ridges refract the light, throwing it in various directions and thoroughly diffusing it in ad dition to presenting an attractive pattern to the eye. While the lines of this converging portion when viewed in diametrical section may be somewhat varied the preferred construction is illustrated in which this portion is bowl-shaped. This converging portion is closed at the bottom by a center portion 8, which is preferably of clear glass, although it may be opal or translucent if desired.

The portions hereinabove described are integral with each other, thus making a totally enclosed unit which has the advantage of being dustproof as well as presenting an attractive appearance to the eye and giving a maximum of light without causing eye strain.

Having thus described my invention, what I claim as new and desire to secure by Letters Patentis:

l. A one-piece totally enclosed lighting unit having a semi-transparent, trunco-conical upper portion provided with means for attaching the unit to a supporting fixture, an integral and continuous cylindrical portion depending from the lower rim of the conical portion, a converging portion below the cylindrical portion and integral and continuous therewith, said converging portion,

being of substantially clear rippled glass, and a bottom portion which is approximately horizontal and is integral and continuous with the converging portion.

2. A one-piece totally enclosed lighting unit having a semi-transparent, trunco-conical portion provided with means for attaching the unit to a supporting fixture an integral and continuous cylindrical portion depending from the lower rim of the conical portion, said conical and cylindrical portions being integral and formed of semitransparent glass, a bowl shaped converging portion below the cylindrical portion and integral and continuous therewith, said converging portion being of substantially clear rippled glass, and a horizontal bottom portion of circular outline integral and continuous with the converging portion and formed of substantially clear glass.

In witness whereof, I have hereunto subscribed my name.

FLORENCE L. GRANT. 

